Abstract
The morbidity and mortality of lung cancer are among the forefront of various cancers, and it is one of the major cancers that seriously threaten human life and health. It is well known that the abundant angiogenesis and lymphangiogenesis in tumor tissues play an important role in tumor growth and metastasis. In addition, The epithelial-mesenchymal transition (EMT), which facilitates the tumor cell metastasis and invasion, is triggered by many stimuli, such as matrix metalloproteinases 2 (MMP2), MMP9, and transforming growth factor-β1 (TGF-β1). At present, various studies have confirmed that both moderate intensity constant load exercise (MICE) and high-intensity interval exercise (HIIE) have a positive therapeutic effect on the treatment of lung cancer, delaying the progression of lung cancer. However, little is currently known regarding whether its specific treatment mechanism is related to blood vessels, lymphatic vessels, and EMT. Indeed, we found an increase in angiogenesis and lymphangiogenesis in lung cancer tissues. However, compared to high-intensity interval exercise, moderate intensity constant load exercise can significantly reduce tumor growth in the lung independent of blood vessels and lymphatic vessels. It is worth noting that moderate intensity constant load exercise can also reduce the level of MMP9 in lung cancer tissues, which may control tumor metastasis to a certain extent. In addition, high-intensity interval exercise reduces the expression of MMP2, but it tends to enhance EMT and activate TGF-β1. Taken together, our findings suggest that, whether it is tumor growth or metastasis, moderate intensity constant load exercise has a better therapeutic effect on lung cancer than high-intensity interval exercise.